Field of the Invention
The present invention relates to a conversion processing technology for image data.
Description of the Related Art
A printing apparatus receives a drawing command (page description language (PDL) command) described in PDL from a personal computer (PC) or a web server (hereinafter, host), and performs print processing according to the command. A document for printing may include a bitmap drawing. The bitmap drawing generally has a size as the PDL drawing command larger than those of other drawings such as graphics or texts, and transfer time to the printing apparatus is accordingly longer. This leads to an increase of total printing time. Further, in print services using a cloud environment, which is a recent focus of attention, the transfer time is a bottleneck in total printing time in many cases.
Japanese Patent Application Laid-Open No. 7-182502 discusses a technology for reducing a size of a PDL command by performing a thinning operation for a bitmap. To suppress deterioration of a drawing, an influence on a user engaged in printing can be suppressed by interactively instructing a thinning position.
However, the thinning operation may cause a loss of information in the bitmap, thus generating an output unintended by the user. For the bitmap, in many cases, geometric transformation (affine transformation) such as enlargement or rotation is designated. For example, when only enlargement is designated, enlargement processing is generally carried out for the bitmap in the printing apparatus. On the other hand, for example, when printing is performed in a printing apparatus that cannot carry out rotation processing for the bitmap, if enlargement and rotation are designated for the bitmap, the host side is not allowed to carry out only the rotation processing in principle. It is because since exchanging is impossible between enlargement and rotation and a processing order is complex, the host side cannot simply carry out only the enlargement processing.
The influence of the processing order will be described referring to FIGS. 12A and 12B. FIG. 12A illustrates an example when rotation processing is performed after enlargement processing has performed for a bitmap. FIG. 12B illustrates an example when enlargement processing is performed after rotation processing has performed. Results are not similar. Thus, when enlargement and other transformation processes for the bitmap are included, the host side must carry out all the conversion processes. This increases a size of a bitmap drawing command. As a result, a size of a PDL command increases.